The present invention relates generally to a fluid control system, and in particular, to a fluid control system for various office furniture devices, including various chair components.
Typically, various office furniture devices, including for example, chairs and worksurface members, are configured with moveable support members. For example, office chairs generally can be configured with moveable support arms, support columns, backrests and seats. Likewise, worksurface members or assemblies often are configured with moveable support legs and the like.
Often, the movement of such support members is controlled with mechanical systems, including for example various ratchet mechanisms, gear trains and the like. Typically, support members controlled by such devices have some play in them due to the tolerance buildup between the interconnected parts, such that the support members, or components connected thereto, may feel loose to the user. Moreover, many such devices have a limited number of adjustable positions, and therefore are not infinitely adjustable. In addition, such systems are passive, meaning that they typically require the user to move the support member, or component supported thereon, between one or more positions. Alternatively, when electromechanical devices, including for example various screw devices, are used, a power source, which can be expensive and bulky, must be provided.
Alternatively, the movement of the various support members or components can be controlled with various pneumatic or gas spring devices. Although such systems are active, meaning that they typically are capable of moving the support member or component in at least one direction without the assistance of the user, they generally exert large amounts of pressure, which must be countered by the user to move the support member or component in the opposite direction. Moreover, such devices typically move rather quickly and the adjustment thereof can feel erratic to the user.
In other alternatives, the movement is controlled with various hydraulic devices. Often, office furniture devices employing hydraulic devices are relatively heavy, and may require various power sources for pumps and the like, both of which limit the portability of the devices. In addition, such devices often include numerous lines, seals and other parts, which can significantly add to the cost of the device and which may require frequent, periodic maintenance.
Briefly stated, in one aspect of the invention, a chair includes a first and second support member. The first support member has a fluid passageway formed within at least a portion thereof. A first piston, having a first and second end, is moveably disposed in the fluid passageway. The second support member is coupled to the first end of the first piston. A fluid supply is disposed in the fluid passageway and communicates with the second end of the first piston. A second piston has a first end and a second end, wherein the second end communicates with the fluid supply. A force applying element biases the first end of the second piston. A fluid flow controller controls a flow of the fluid supply and is operable between at least an open and closed position, wherein the fluid supply is allowed to flow between the first and second pistons when the controller is in the open position and wherein the fluid supply is not allowed to flow between the first and second pistons when the controller is in the closed position.
In one preferred embodiment, the fluid supply comprises a magneto-rheological fluid, and the controller comprises a magnet. The magnet is moveable between a first and second position, wherein the magnet applies a magnetic field to the fluid supply when in the first position.
In an alternative preferred embodiment, the fluid supply comprises a hydraulic fluid, and the controller comprises a valve. The valve is moveable to an open position to allow the fluid supply to flow between the first and second positions.
In a preferred embodiment, the support member comprises a one-piece member having an interior surface defining the fluid passageway. Also in a preferred embodiment, a second fluid passageway is formed in the support member, and the second piston member is slidably disposed in the second fluid passageway.
Preferably, one of the support members comprises a chair component. For example, in one embodiment, the second support member comprises an armrest member.
In another aspect of the invention, an office furniture device comprises a support member having a fluid passageway formed within at least a portion thereof and a piston slideably disposed in said fluid passageway and having a first and second end. A magneto-rheological fluid is disposed in the fluid passageway and communicates with the second end of the piston. A magnet is moveable between at least a first and second position, wherein the magnet applies a magnetic field to said magneto-rheological fluid when in said first position. An actuator is connected to said magnet and is operable between at least a first and second position, wherein the actuator moves the magnet to the first position when the actuator is in the first position and wherein the actuator moves the magnet to the second position when the actuator is in the second position.
In other aspects of the invention, a method for operating a chair is provided, along with a method for operating an office furniture device.
The present inventions provide significant advantages over other office furniture devices and their respective control systems. For example, by providing a support member having a fluid passageway formed therein, the system can be greatly simplified. Moreover, in a preferred embodiment, wherein the fluid passageway and controller, or control system, are locally contained within or adjacent the support member, various extraneous parts, such as conduit lines, are avoided, thereby reducing the cost of the device and the expense of maintaining it. Moreover, by using a simple force applying member, the additional cost and weight associated with using various pumps and electromechanical devices is avoided, thereby making the office furniture component portable. In addition, such a mechanical system avoids any interference with electrical devices such as computers. At the same time, the use of a fluid control system, with a controller, provides infinite adjustment of the device and a rigid feel when in the closed position.
The use of a magneto-rheological fluid, together with a moveable magnet, also provides significant advantages. For example, the simple movement of the magnet between the first and second positions can be used to apply a magnetic field to the magneto-rheological fluid, which provides a very rigid feel to the device. In this way, the use of various electrical circuits to create the magnetic field is avoided, which in turn simplifies the device and eliminates the need for a power source, which can interfere with the operation of various office equipment, such as computers.
The present invention, together with further objects and advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings.